Interlocking overhead trolleys.



' s. B. STEWART, JR. INTERLOGKING OVERHEAD TROLLEYS APPLICATION FILED JULY 2, 1908.

.1 1 0 2 Patented June 16, 1914.

INVENTD'RI WW 7 EIAMLIEL ELEWEWARTJ'R COLUMBIA PLANouRAPr-x 10., WASHINGTON, D. c.

EINTTED STATES PATENT OFFICE.

SAMUEL B. STEWART, JR., 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL. ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INTERLOCKING OVERHEAD TROLLEYS.

Specification of Letters Patent.

Patented June 16, 1914.

Application filed July 2, 1908. Serial No. 441,623.

To all whom it may concern Be it known that I, SAMUEL B. STEWART, Jr, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Interlocking Overhead Trolleys, of which the following is a specification;

This invention relates to electric railway cars which are operated by current of one character over part of the system and by current of a different character over the remainder of said system. A separate trolley is provided for each kind of current, and the object of the present invention is to prevent both trolleys from occupying their operative or service positions at the same time, but to cause the one in service to lock the other in a depressed or inoperative position.

inasmuch as the pantograph trolley customarily used on the higher potential or alternating current portion of the system is provided with pneumatic mechanism for raising it into contact with the overhead conductor, 1 have utilized the pneumatic pressure to actuate the interlocking devices between the two trolleys. The lower po tential or direct current trolley is preferably of the pole type, mounted on a swiveling stand and elevated by springs. When pulled down it engages and'opens a valve which controls the pipe supplying air to the cylinder of the pantograph trolley. Between said valve and cylinder is a branch pipe conveying air to a movable abutment which operates a latch acting to hold the pole trolley in its depressed position. Con sequently as soon as the motorman admits air to raise the pantograph trolley, the pole trolley becomes locked, and cannot be raised until the air pressure is taken off the pantograph trolley and it has dropped. Moreover when the pole trolley rises to its service position it causes a closing of the valve controlling the air pipe, so that the motorman cannot inadvertently raise the pantograph trolley while the pole trolley is up.

The accompanying drawing is a representation more or less diagrammatic of a pair of trolleys and interlocking devices embodying my invention.

The pantograph trolley 1, for use with high potential or alternating current, is of any suitable construction, and is provided with a cylinder 2 containing pistons 3 for effecting the raising of the trolley shoe 4 into contact with the overhead conductor carrying high potential or alternating current, and for maintaining it there. Air for actuating said pistons can be admitted between them and exhausted through the pipe 5 under control of an ordinary hand valve not shown.

The pole trolley 6, for use with low potential or direct current, is of any suitable construction, and is provided with tension springs 7 to urge the trolley wheel 8 up into operative contact with the overhead conductor carrying low potential or direct current. It can be pulled down by the rope 9 and engaged with the retaining hook 10.

A valve 11 is arranged to control the air pipe, being preferably closed by a spring 12 and seating against a centrally apertured septum 13 in a casing it. The stem 15 of the valve, which is substantially smaller than the aperture in septum 13, terminates adjacent to the pole trolley 6, and in such a position with reference thereto that when said trolley is depressed it will strike said stem and force the valve open, as shown in the drawing.

A movable abutment, preferably a piston 16 in a cylinder 17, is exposed to the pressure in the air pipe between the valve casing 1i and the pantograph trolley; the cylinder 17 being suitably connected with said pipe, as by means of the branch pipe 18. A helical spring 19 urges the piston toward the airinlet of the cylinder. Carried by the piston is a suitable latch or bolt 20 adapted to engage with and lock the trolley 6 when the latter is depressed; as for instance by entering a hole in a lug 21 projecting from said trolley. Said lug is brought down in line with said bolt when the trolley 6 is pulled down, so that when the compressed air is admitted to the pipe 5 by the motorman for the purpose of raising the pantograph trolley 1, said air enters the cylinder 17, overcomes the tension of the spring 19, and forces the bolt into locking engagement with said lug. It thus becomes impossible to raise the pole trolley so long as the pantograph trolley is kept up by the air pressure. But when said pressure is released and the trolley 1 drops, the spring 19 retracts the bolt 20 and leaves the pole trolley 6 free to be disengaged from the hook it) and raised by its springs 7. At the instant the trolley 6 rises off the stem 15, the spring 12 closes the valve 11, so that no air can be admitted to the pantograph trolley cylinder 2 so long as the pole trolley remains up.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination of a pair of trolleys, spring means for moving one of said trolleys into operative position, pneumatic means for moving the other trolley into operative position, a lock for the spring actuated trolley movable into engaging position under the pneumatic pressure of the other trolley, and a valve for controlling said pneumatic pressure positioned to be opened by movement of the spring actuated trolley into inoperative position.

2. The combination of a pair of trolleys, spring means for moving one of said trolleys into operative position, a cylinder and piston means for moving the other trolley into operative position, a fluid supply system for said cylinder and piston means, a lock for said spring actuated trolley having a cylinder and piston means connected to said fluid pressure system, and a valve for said fluid pressure system arranged in the path of movement of said spring actuated trolley to be actuated thereby upon movement of said trolley into and out of inoperative-position.

3. The combination of a pair of trolleys, one connected in a circuit adapted for current of one character and the other connected in a circuit for current of a different character, pneumatic means for raising one trolley, a pneumatic locking device for the other trolley, and a. valve for said raising and locking means controlled by the latter trolley.

4. The combination of a pair of trolleys, one connected in a circuit adapted for current of one character and the other connected in a circuit adapted for current of a dilterent character, pneumatic means for raising one trolley, pneumatic locking means for the other trolley, and a self-closing valve for admitting air to said raising and locking means and adapted to be opened by depression of the latter trolley.

5. The combination of a trolley connected in a circuit adapted for current of one character, a second trolley connected in a circuit adapted for current of a different character, a cylinder and piston device for raising the first trolley, a lug on the second trolley, a locking bolt adapted to engage said lug when the trolley is down, a movable abutment for actuating said bolt and exposed to the same fluid pressure as said cylinder and piston device, and a self-closing valve controlling said pressure fluid and adapted to be opened by the depression of the second trolley.

In Witness whereof, I have hereunto set my hand this 1st day of July, 1908.

SAMUEL B. STEWART, JR.

lVitnesses BENJAMIN B. HULL, HELEN Onronn.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G. 

